I'd take a Whipple over a Pro Charger/Centrifugal any day of the week. A Whipple may not run quite as cool of an air intake charge as a Centrifugal such as a Pro Charger, but they run cooler than a Roots supercharger----And those Pro Charger systems look look sucky ugly under a marine engine hatch (just my .02)

...and I would still go with an AFR 335cc Cnc'd ported head vs their 357cc head for a 572cid engine running @6000rpm and below----and that goes for the Cam profile too---go more for the Torque from than a Horsepower number----I'm just sayin' brother. Most of these BBC marine engines usually respond well and make good reliable power around the 5500rpm range so, try to target your Cam selection for that rpm.

I don't know if you're looking for a builder or not, but here's some good helpful advice--- do yourself a huge favor and call "articfriends" (Steve Smith/Smitty) here on OSO...he;s a Marine Hi-Perf engine builder and Tuner with a dyno and has done many "fix it" jobs that customers had gotten screwed over for various reasons. Steve is on here in the Technical Q&A section quite frequently and is brutally honest, experienced and very knowledgeable, and is a super detailed tuner when it comes to all this stuff. And he can help you with the right cam and head selection. I've know Steve for over 20- years. He's at least worth a phone call.

David Vizard was speaking to some really good supercharger tech advancement the past decade or so.

Speaking largely to the Magnuson Superchargers, and the end feed style with MPI. Essentially they have a freewheeling option for cruising etc, so they don't have much parasitic losses.

This is great for automotive applications. Marine light throttle on plane would be working enough to consume the blower feed. You still may pull a vacuum depending on your low cruise speed, but optimally, at your comfortable higher end cruise speed, the blower is not producing boost. Not making pressure, so not heating the air, and not wasting crank energy from making pressure.

Still benefiting from the blower air flow, filling the void of the vacuum you would be pulling without it.

You can then use the rest of the rpm/throttle for more spirited boating, getting into the boost levels.

Would only a 6/71 + sized blower would be able to support that?


How would a centrifugal supercharger with lag perform on large rough waters when you had to work the throttles to the water?
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Kaama is often very reasonable here on OSO. On many of my deep dive searches for info...his posts go way back. A dedicated enthusiast for certain.
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I've really appreciated his humble words of wisdom.

Bottom line...were all here to push the envelope of the sport/hobby....'cause that is a large part of the draw and fun of it. Along the way, we're going to make mistakes...if we don't...we're not trying hard enough.

One factor...there is no current comprehensive marine performance book. The Denis Moore offerings are unobtanium. It takes a lot of effort to harvest the OSO data over the years.

OP: M3 supercharger, I hope it works out for you, let us know how it goes...looking forward to the pics.

I had a look at the specs. Good for 1200hp from 400-600 base engine. I run in salt water...so I always think of the worst case, and I don't like a water to air charge cooler, unless it was stainless...and you of course lose some thermal conductivity with 316L.

I don't have room for air coolers...but I should not be running more than 5-6psi. Raising or cutting into the sun pad, would get in the way of enjoying the wife getting the good news from the sun.

All depends on your HP goals. A M-3 gets "small" quick on a 572 if your trying to make real HP, if your talking low hp like 700,800, 900, it will be plenty fine. A 572 should make 700 on its own though. All this talk about intake runner "head CC's" between the 335s AFRs and 357s, keep in mind AFR uses the SAME EXHAUST PORT in the 315, 335 and 357. To best of my knowledge the 357 exhaust port will flow exactly same as the 335, ZERO exhaust flow advantage. As far as the Intake, you can force feed air thru a mediocre port and the 335 is far from mediocre. Im not ambitious enough to go look it up this morning but if you research the various AFR heads, you will see as they get bigger and bigger they actually flow LESS at the lifts most marine engines use so do your research there. Alot of boater guys forget the majority of boat engines DONT turn the rpms to come close to using alot of these "big" intakes, heads, huge cams etc.
As far as prochargers vs accel tq, vs boost, yeah sure, put one on something and pulley it to make 3 or 4 lbs of boost on top end, of course your not going to see a bunch of mid range gain. alot of guys whove never owned either a whipple or procharger ramble on about this debate. My M-3 was pulled up to make 12 lbs on my everyday tune, Id have to go back and look at my dyno sheets but I made over a 1000 ft lbs of peak tq and over 800 by 3000, enough to shear off billet vert shafts and props hafts jumping on plane. Smitty

To each his own , My 35yr old pile of fiberglass with 510's and Vortech centrifugal superchargers , has no problem getting on plane in under 10 seconds , will run over 100mph any time , and nobody told me my engine set-up looked like ****.

You have one of the better looking installs I have seen, love the custom intercoolers.

This is coming from a old school street rod/ biker guy so I am a bit picky on motor looks.

M3 on that big engine ought to make some JAM. Sounds fun

I'm curious, what boat are you putting this motor in ?

Oh its going in a smaller boat... its in a baja h2x.... I know over kill and some with think im dumb but it's what I want... its a fun smaller boat with my 509 and procharged set up... so be even more fun with the bigger stuff in it...

Yes i have read alot on here and to be honest thats all I usually do is read and not post or comment or any of that... so I tried to message smitty and it said I had to have ten post so thats why I registered and make a post... all this knowledge does help a ton... and as far as the 335s thats what I was originally going with and then a buddy thats helping me with this stuff actually called and talked to a guy at afr and that's where he said I would be better with the 357...
And then all this talk about the spinning a motor at higher rpms.. thats not what i want.... my 509 is that way a couple turb taking off but on plane the thing is great... its getting alittle tired now but still runs good and pulls good... but the place that built my motor the thing made peak power at like 6500 rpms... so been told that motor is way over cammed and that's why it's such a turd on take off... so I have had my run of bad luck paying lots of money only for it to be done wrong...(long story won't even go into the first 3 years of the 509)... so I know there is plenty of knowledgeable people in the marine world so trying to soak all in and do it right this time....